Dun, Chaochao Jeong, Sohee Kwon, Deok-Hwang Kang, ShinYoung Stavila, Vitalie Zhang, Zhuolei Lee, Joo-Won Mattox, Tracy M. Heo, Tae Wook Wood, Brandon C. Urban, Jeffrey J. 2024-01-19T12:03:51Z 2024-01-19T12:03:51Z 2022-07-08 2022-04 0897-4756 https://pubs.kist.re.kr/handle/201004/115276 Chemical interactions on the surface of a functional nanoparticle are closely related to its crystal facets, which can regulate the corresponding energy storage properties like hydrogen absorption. In this study, we reported a one-step growth of magnesium (Mg) particles with both close- and nonclose-packed facets, that is, {0001} and {2 (11) over bar6} planes, on atomically thin reduced graphene oxide (rGO). The detailed microstructures of Mg/rGO hybrids were revealed by X-ray diffraction, selected-area electron diffraction, high-resolution transmission electron microscopy, and fast Fourier transform analysis. Hydrogen storage performance of Mg/rGO hybrids with different orientations varies: Mg with preferential high-index {2 (11) over bar6} crystal surface shows remarkably increased hydrogen absorption up to 6.2 wt % compared with the system exposing no preferentially oriented crystal surfaces showing inferior performance of 5.1 wt % within the first 2 h. First-principles calculations revealed improved hydrogen sorption properties on the {2 (11) over bar6} surface with a lower hydrogen dissociation energy barrier and higher stability of hydrogen atoms than those on the {0001} basal plane, supporting the hydrogen uptake experiment. In addition, the hydrogen penetration energy barrier is found to be much lower than that of {0001} because of low surface atom packing density, which might be the most critical process to the hydrogenation kinetics. The experimental and calculation results present a new handle for regulating the hydrogen storage of metal hydrides by controlled Mg facets. English American Chemical Society Hydrogen Storage Performance of Preferentially Oriented Mg/rGO Hybrids Article 10.1021/acs.chemmater.1c03714 1 Chemistry of Materials, v.34, no.7, pp.2963 - 2971 Chemistry of Materials 34 7 2963 2971 N scie scopus 000813386800001 Chemistry, Physical Materials Science, Multidisciplinary Chemistry Materials Science Article ENERGY ABSORPTION KINETICS